Conventional microelectronics fabrication techniques often involve the fabrication of devices, for example microprocessors, on a semiconductor substrate by the selective doping of regions of the substrate and deposition and patterning of various layers of dielectric, metals, and semiconductor materials. These layers of materials are often very thin, on the order of microns. The resulting devices are effectively two dimensional. Providing additional functionality, for example, by the addition of additional transistors or other features to a device, conventionally requires the surface area of the device to be increased, subsequently reducing the number of devices that can be formed on a single wafer or included within a package of a given size.